Motor vehicles driven by a plurality of axles can be divided into those with a hang-on four-wheel drive wherein a primary axle is driven permanently and a secondary axle is connected if required, and those with permanent four-wheel drive wherein both axles are driven permanently. The design of the driveline is largely influenced by the arrangement of the engine in the motor vehicle, i.e. whether it is arranged in the front or at the rear, and whether it is positioned in the longitudinal or transverse direction. At the same time, the automotive industry desires continuous improvements such as lightweight and compact solutions for differentials.
There already exist prior art combined differential assemblies which permit differential movements between the two sideshafts of one of the two driven axles on the one hand, and between the two driven axles relative to one other on the other hand.
EP 043 806 B1 or EP 1 239 188 B1 propose combined differential assemblies which each comprise a first engine-driven differential for distributing the torque to the front axle and to the rear axle, and a second differential connected in series thereto for distributing torque to the two sideshafts of the front axle. The first differential is provided in the form of a planetary differential whose web is firmly connected to the carrier of the second differential.
From DE 33 11 175 A1, there is known a similar differential assembly wherein the first differential is provided in the form of a planetary differential or bevel gear differential.